JPS61127299A - Acoustic device for vehicle - Google Patents

Abstract

PURPOSE:To reduce the degree of influences of leaked sounds upon the other passengers by attenuating a prescribed high sound band of the acoustic signal inputted to a high sound band attenuator through a selecting device and amplifying this attenuated acoustic signal and reproducing it with a speaker only for a passenger. CONSTITUTION:Individual passengers connect selectively selecting switches 21a-21d to fixed contacts P0-P3 in accordance with their desires. Then, acoustic signals of various selected programs are inputted from connected cassette decks 1 and 3 and tuners 2 and 4 to low-pass filters 22a-22d through output circuits 10-13. Low-pass filters 22a-22d attenuate high sound components of acoustic signals and input them to headphone amplifiers 23a-23d. Consequently, headphone amplifiers 23a-23d amplify acoustic signals whose high sound band of 1-2kHz is attenuated, and reproduced sounds where the high sound band is attenuated are radiated from headrest speakers 24a-24d toward ears of passengers.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a vehicle audio system that allows each passenger to individually listen to different programs in a vehicle interior.

Conventional technology Conventional vehicle audio systems include: (1) individual listening systems in which headphones are placed for each passenger so that each passenger can listen to a different program; Nine devices equipped with speakers (August 1986)
Published by Nikensha Co., Ltd. [0AFI GRAP[OJ
(March issue, p. 816) is in practical use.

Problems to be solved by the invention However, in nine devices using the headphones,
In addition to causing an unpleasant pressure sensation when using headphones, there are disadvantages in not being able to use them for drivers who are required to listen to external sounds while driving because the area around the ears is sealed and external sounds are insulated. be.

On the other hand, in the case of a device in which speakers are arranged in the headrest, the above-mentioned disadvantages can be eliminated, but on the other hand, the sound emitted from each speaker becomes leakage sound to other occupants other than Todoroki. Since the afC can be listened to, it should not be used as a reproduction means for an individual listening system.

The present invention has been devised in view of the conventional situation (and focusing on the fact that leakage noise has different effects on other occupants depending on its frequency), as has been made clear by the Nokneller experiment, etc. To provide a dual-use acoustic device that enables individual listening using speakers without being affected by leaked sound by attenuating and reproducing high-frequency sounds that have a strong influence on other occupants as leaked sound. 0 Tth Means for Solving the Problems In order to solve all of the above-mentioned problems, the present invention provides a plurality of acoustic sources that output different acoustic signals, and a plurality of acoustic sources provided corresponding to the occupants. a source selection device that can be selectively linked to each output circuit; a high-frequency attenuation device that attenuates a predetermined high-frequency range of an acoustic signal inputted through the source selection device; and amplifies the attenuated acoustic signal. and a speaker dedicated to each crew member disposed close to the ear position of the crew member and reproducing the acoustic signal.The crew member then operates a selection device to select a desired sound source. The acoustic signal output from the acoustic source is input to a high-frequency attenuation device via a selection device.In the high-frequency attenuation device, a predetermined high-frequency range of the acoustic signal is attenuated. The nine acoustic signals are amplified and reproduced by the passenger-only speakers.At this time, the reproduced sound is subjected to the above-mentioned attenuation process to attenuate the high frequency range that may interfere with the hearing of other passengers. The occupants can listen to different programs under conditions where the influence of sound leakage from other speakers is extremely low.

Examples Examples of the present invention will be described below with reference to the drawings. 1st
The figure shows a first embodiment of the present invention, in which a plurality of sound sources are provided, including a first cassette deck lJ first chainer, a second cassette deck 3° and a second chainer. .3. On the output side of Chainaco and Hiroshi, there is a changeover switch that operates in conjunction! ,≦,7. t
is provided. the first cassette deck/and the first
Nine changeover switches installed on tuner λ side? , 4 are provided with a fixed contact P1゜ which is connected to the main amplifier 2, and a fixed contact 10 ps''1) which is connected to the first output circuit 10% and the second output circuit. 2nd cassette deck!, 2nd chainer Hiroshi side changeover switch r, 4
, fixed contacts //1) and //p of the third output circuit /co and the fourth output circuit 13 are provided.

On the output side of the main amplifier 2, there are door speakers/6. mounted on the doors/IA, # of the automobile 13 as shown in FIG. /7 and nine rear speakers installed on both sides of the rear parcel shelf /9. :w is provided. On the other hand, the first to fourth output circuits 10. //, /J.

/JIC is a selection switch that is a source selection device, 7.7
a.

Fixed contacts '(1+Ple'Snow+PR) are provided.The movable contacts of each selection switch 2/a, 'b, a, and 4 are provided with low-pass filters a, b, and high-frequency attenuators. The low-pass filters n&, b, c, and d to which a and d are connected have characteristics capable of attenuating the high frequency range of 1 to 2 KHz or more and filtering the frequency band below this.Each low-pass filter On the output side of ua, b, c, and d, there is a headphone amplifier 2 which is a means for amplifying the acoustic signal.
Ja, 'b, a, d are provided (#), and the headphone amplifier ua, b.

Headrest speakers Jla, b, a, and d, which are dedicated speakers for each passenger, are provided on the output side of the speakers c and d. The headrest speakers j4ta, b, a.

d is composed of speakers θR*BT- for each left and right channel, and is shown in FIG. a, and are arranged close to the left and right ears of the occupants seated in the front and rear seats S, S.

In this embodiment with the above configuration, when each passenger listens to a common program, ±
Like the 1st cassette deck/, the changeover switch on the 1st chain naco side! , Close to Otowoburi/Main Anbuta side. As a result, the first cassette deck 1 and the first tuner λ are connected to the main amplifier and are in the 9 state. Therefore, it is necessary to turn on the switch of the first cassette deck or the first channel, and the door speaker/4. /'!
, +) Playback sound is emitted from the Yaspee power iq, 2o so that all passengers can listen to the same program.Next, if each passenger wants to listen to a different program, selector switches 4, 7 . r and P are interlocked to close each output circuit 10 degrees to the //, /J, and /J sides, as shown by the dashed line in Fig. 1. At this time, each cassette deck L, 3, tuner 2
．． Hiro is set to play and receive different programs. Then each output circuit 10. Audio signals of different programs are supplied to //, /ko, /31C from the corresponding cassette decks /, 3 and tuner decks, -. Therefore, each passenger selects the selection switch 2 according to his/her own wishes.
/ l! L Ibe O, de, the fixed contact POe
Select and connect to Pi e P + P3. This allows each output circuit 10. //, /2. /
, 7, the audio signals of nine different programs selected from nine connected cassette decks 1, 3, tuner 4' are input to low-pass filters j2a, b, a, d. The low-pass filters a, b, a, and d are.

The high frequency component of the acoustic signal is attenuated and input to the headphone amplifiers 2Ja, 'b, a, and d. Please be careful d
Pig headphone amplifier 2Ja, b, o, a are i~2KHz
The high-frequency range is attenuated and the next acoustic signal is amplified, and the reproduced sound with the high-frequency range attenuated is radiated from the headrest speakers 244a, b, a, and tl toward the ears of the occupant. For example, if you hear the sound of another program being played from the seat next to you,
In other words, even if leakage sound occurs, the occupant will not be bothered by the leakage sound because, as described above, the high-pitched sound component that causes harshness and has a large impact on the auditory sense is attenuated. This allows you to listen to the music you want with full concentration. Note that the sound emitted from the headrest speakers has only the high frequency range attenuated, and the high frequency range is not completely eliminated, so the sound does not feel strange to the occupant.

81st embodiment of the present invention, each headrest speaker 21a, 21a, 21b, 21a, 21d is designed to automatically control the volume of each headphone amplifier ua, 21d according to the noise level. and headrest speakers, 2
Between 1Ia, b, a, and 4 are volume limiters Qta, b,
a, a is interposed, and the volume limiter, 2ja,'
b, c, d are headphone amplifiers: L3a, b, a, d
It has a function to limit the upper limit level of the amplified sound to a set level where sound leakage is not a concern.

Microphone cores for noise detection are connected to b, a, and a. In such embodiments, the headrest speakers j, 4! The playback volumes of a, 'b, o, and d are controlled by the volume limiters #a, b, a, and (1) to a level that is not noticeable as leakage sound.And when the ambient noise level increases, , taking masking due to noise into consideration, the setting level is changed to a carefully large value according to the noise level output from the noise detection circuit 27.Therefore, while minimizing the influence of leaked sound on other occupants, Moreover, the passenger can listen to the program at the optimum volume without being affected by noise.

FIG. 4 shows an eighth embodiment of the present invention, in which when each passenger selects the same sound source, the attenuation process for the high frequency range is avoided because there is no influence from leakage sound. It's just in case. That is, each low-pass filter JJa,
Relay 4a is provided by bypassing gates b, a, and d, and is always open and closed when excited by the output of gate 2g.

b, a, and 6 are interposed. A connection between the AND gate j& and the power supply 29 is connected to the output circuit 10. //, /J,
A plurality of parallel circuits 30 corresponding to /j. J/ , ,
7 pieces, 33, and each parallel circuit, 101. ? /,,,? The selection switches /a and b have fixed contacts connected to the corresponding selection switches /a and 3J, respectively.

The first to fourth driven switches a are linked to c and d.

b, a, and a are provided. The movable contact of the first driven switch 1daa is connected to the power source 2f, and the movable contact of the first driven switch 1daa is
~4 driven switch? lb, o, d are the AND game)
21.

In this embodiment with the above configuration, if the two selection switches j/a, b, a, and d shown in the figure select the same sound source, the driven switches 3ub and a+6 of $2 to 4
are connected, for example, to the same parallel circuit 30, and the first driven switch is connected to the same parallel circuit 30f and the power source 9. Therefore A
ND gate u is turned on and each relay! fa, b, c
, d is excited and becomes closed.

The acoustic signal is therefore passed through a low-pass filter ηa.

b, o, dt-Detour, headphone amplifier illusion a.

b, Or d (?4x diagram) and is amplified.

Headrest speakers, 21Ia, b, a.

d, it is possible to obtain natural reproduced sound without attenuation in the high range. In addition, in case any crew member wants to change the sound source selection, use the AND gate, f
is OFF, and each low-pass filter 2.2a*b
Of course, high frequency components are attenuated by l a and +IK.

Also, the telephonic sound shown in the second embodiment [17 Otsuta #a,'b].

If the c, d% microphones and noise detection circuit 27 are used in the third embodiment, it is possible to further control the amount of attenuation according to the noise level. provides multiple acoustic sources,
Depending on the occupant's selection, a different sound signal from each sound source is played through a speaker dedicated to each passenger, and a predetermined high frequency range of each sound signal is attenuated, thereby creating an oppressive feeling similar to an individual listening system using headphones. is born O
Disadvantages such as not being able to be used by one driver can be eliminated. In addition, regarding leakage sound that may interfere with the hearing of the occupants sitting next to you, the high-frequency range, which has the greatest impact, is attenuated, which minimizes the interference caused by leakage sound.
This makes it possible to use a speaker as a reproduction means in an individual listening system.

In addition, in the second embodiment, since the volume is controlled to be below a predetermined level, the influence of leaked sound can be further reduced.

Moreover, since the volume level is controlled according to the noise level, the optimal volume that can withstand the noise can always be obtained.In addition, in the eighth embodiment, when all the passengers select the same sound source. Since high frequency attenuation processing is automatically avoided, the sound quality characteristics when listening to the same program can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block circuit diagram showing a first embodiment of the present invention;
Fig. 2 Ic is an explanatory diagram showing the speaker arrangement structure of the same embodiment, No. 81 is a block circuit diagram showing the second embodiment of the present invention, and Fig. 4 is a block circuit showing the third embodiment of the present invention. The figure is 0/, 3... cassette deck (Kyokyo source), 2゜Hiro・
... Tuner (acoustic source), 10. //, /ko, /3...output circuit, 2+/a, 'b, a, tl・
...Selection switch (source selection device), za, b, a,
a/o-pass filter (treble attenuation device R), jJa,
b.C. d...Headphone amplifier (means for amplification), 7tI
a.

Claims (1)

[Claims] (1) multiple acoustic sources outputting different acoustic signals;
a source selection device that is provided corresponding to a passenger and can be selectively linked to each output circuit of the sound source; and a high-frequency range that attenuates only a predetermined high-frequency range of an audio signal inputted through the source selection device. A vehicle acoustic device comprising: an attenuation device, a means for amplifying the sound range signal whose high frequency range has been attenuated, and a speaker dedicated to each passenger that is placed close to the ear position of the passenger and reproduces the sound signal. Device.